In previous decades, recording a video entailed carrying a separate, relatively large and bulky device called a video camera recorder, or camcorder. In the 1980's and into the 1990's, these camcorders were so large and heavy that a person often used a shoulder to support the camcorder while filming a video. By the late 1990's and into the 2000's, camcorders became increasingly smaller and lighter. A camcorder from this era eventually weighed less than a few pounds and was supported with one hand while filming In each of these previous decades, video recording was usually reserved for special events and long recording times. The videos were recorded to tape, followed by optical discs, and then to magnetic disks. Such long-form personal videos were typically “shared” as part of an hours-long social event by inviting people into one's home and screening the video on a television.
By around 2010, a new type of video camera recording device, or video camera, became popular: the smart phone. The quality of video recording on smart phones has improved such that smart phone videos now rival those recorded by separate camcorders from just the previous decade. Many people carry a smart phone with them at all times, so a video camera is literally always at hand Thus, a person with a smart phone can record high quality video using just one hand and with only a moment's notice. People are therefore recording significantly more videos than in the past. Each smart phone video, however, tends to be shorter than camcorder videos. Smart phone videos are also less likely to be used to memorialize a once-in-a-lifetime occasion like a wedding or graduation. Accordingly, playing smart phone videos as the focal point of a scheduled social event is less common. Nevertheless, people still want to share videos taken by smart phones.
People wish to quickly share special events that have been memorialized in video form using an electronic format that can be distributed to many friends and family members. Thus, smart phone users typically want to distribute videos via email, text, or social media for nearly instantaneous sharing. Unfortunately, sharing videos is difficult. The electronic files of even relatively short videos are large and therefore consume a tremendous amount of bandwidth, which renders electronic transmission problematic. Moreover, even if a video can be transmitted, watching the video takes some amount of time, which may not be available to a recipient given today's busy lifestyle.
Another approach to sharing aspects of an event that is memorialized in video form involves transmitting an image that is intended to be representative of the event. The image is derived from one or more frames of the video. For example, a static collage formed from multiple frames of the video can be produced and then shared via email, text, or social media. A static collage consumes significantly less bandwidth than the video on which it is based. Furthermore, a recipient can view a static collage practically instantaneously. There are two conventional approaches to creating a static collage from a video.
A first conventional approach includes four steps. A video is first decoded into a collection of constituent frames. These constituent frames are presented to an end user. In a second step, the end user is tasked with selecting a number of desired frames from the collection of frames based on composition and visual appeal. Third, the selected frames are provided to a collage creation application. Fourth, the collage creation application creates a static collage based on the frames selected by the end user. The static collage is displayed to the end user, who can elect to share the static collage with others.
This first conventional approach may appear to be quick and easy. Unfortunately, the process is actually quite lengthy and arduous for the end user. A typical video obtained via a smart phone is recorded at 30 frames per second (fps). However, the frames per second for a recording can be higher. With a slow motion capture, for instance, video can be recorded at a rate that is four to eight times higher (e.g., 120-240 fps). Thus, even a relatively short video having a 10-second duration produces at least 300 frames. Consequently, the end user is required to sift through hundreds of frames to select those few frames that the end user wants the collage creation application to include in the static collage. This is a tedious task for the end user. The first conventional approach is therefore impractical for videos having an even moderate duration.
In a second conventional approach, an application, such as the collage creation application, decodes a video to produce a collection of constituent frames as part of the first step. The collage creation application also thins the number of constituent frames to reduce the size of the collection. The surviving frames of the decimated collection are presented to the end user for review and selection. The remaining second through fourth steps are similar to the first conventional approach. Thus, the second conventional approach does reduce the number of frames that the end user has to review in order to select the desired frames for the static collage. For example, just 30 total frames instead of 300 frames may be presented to the end user for a 10 second video.
This second conventional approach can therefore save time for the end user, but other problems arise. The collage creation application decimates the constituent frames by extracting periodic frames from the decoded sequence of frames. The extracted frames are random in relation to the content of the video. The end user is therefore limited to selecting desired frames from a random subset of the entire set of constituent frames of a video. This random subset of frames may be wholly inadequate to represent the event memorialized by the video. For example, the randomly-extracted frames can suffer from bad composition and poor visual appeal, while other constituent frames having a pleasing composition and excellent visual appeal are never presented to the end user. Moreover, the end user may not even see, much less be afforded an opportunity to select from, the constituent frames that include more important aspects of the subject matter of the video.
Thus, conventional approaches to enabling an end user to create a static collage to represent an event that is memorialized by a video have a number of drawbacks. The first conventional approach described above thrusts on the end user the time-consuming and tedious task of reviewing and selecting from hundreds or thousands of constituent frames of a video. Although the second conventional approach partially ameliorates this time-consuming and tedious work, the end user loses the ability to review and select from some of the more desirable frames of the video.